The testing of diverse sample types derived from human, animal, plant sources, food and environmental samples plays a crucial role in modern medical diagnosis and treatment, forensic medicine, food safety, industrial processing among many other fields. However, such analyses are very often related to complex processes that relate to labor-intensive, chemical, biological and physical steps on a fluid sample that will end in the detection of specifically targeted molecules or analytes using optical, electrical and biochemical procedures. In the current state-of-the-art, sample analysis steps remain mainly dominated by complex, large and expensive “robotic” instruments operated by expert technicians in centralized laboratories. Consequently, any technology that would automate the complex reaction and sample processing steps while making them more affordable and less space-consuming would address unmet needs for simple, cost-effective assaying solutions.
As an emerging alternative to the robotic platforms, fluidic or microfluidic technologies open new perspectives in assay processing and automation. In relation to recent developments in molecular biology, nanotechnology and optics, (micro)fluidic based systems comprehend indeed the potential of providing integrated solutions, where all steps from sample preparation and assay processing to signal amplification and detection of multiple targets will be integrated in a fully automated, compact cartridge.
A typical example of a commercially available cartridge-based solution is the GeneXpert molecular diagnostics platform from Cepheid (CA, USA) (http://www.cepheid.com) which realized an advance in fully automated molecular testing from sample input to result reporting. As for instance disclosed by the U.S. Pat. No. 6,893,879, U.S. Pat. No. 6,664,104, U.S. Pat. No. 6,818,185 and U.S. Pat. No. 6,783,736, the Cepheid system demonstrates the integration of micro-fabricated chips and other miniaturized fluidic or analytical components in a cartridge type where steps from the separation of a desired analyte from the original sample fluid sample to assay processing and target detection are being performed.
Beyond the integration capabilities, one fundamental issue of the development of a micro-fluidic based system is the interfacing of the fluidic part which is substantially small and compact as compared to the relatively large macro-environment, as defined by the user samples, reagents and sensing elements.
With this respect, the international Pat. Application WO 2008/030433 for instance describes the use of a cartridge, which is adapted to contain samples and reaction fluids to interface with a micro-fluidic chip for use for DNA analysis tests and other assays performed within the micro-fluidic chip. The microfluidic interface is assured through access ports in connection with microfluidic channels and located on the top side of the associated micro-fluidic chip. The reagents and samples contained in external chambers within a fluidic cartridge are dispersed into the microfluidic chip through nozzles that will be brought in communication with the access ports on top of said microfluidic chip. Within the same spirit, WO 2010/118427 discloses a fluidic interface device that includes a cartridge with microfluidic configuration that is in fluid communication with a microfluidic chip through contact pores.
The state-of-the-art coupling and interfacing of the micro-fluidic based system with the external environment systems, are facing however a real challenge: The integration of maximum functionalities within the micro-fluidic cartridge which leads to a complex and costly “disposable” cartridge or to lower integration properties at the cartridge level resulting in a more complex interfacing device that practically end in complex robotic platforms. The optimal balance between the cartridge complexity/simplicity versus the corresponding interfacing system simplicity/complexity is still an open mostly unresolved issue.
In knowledge of these shortcomings the current invention concerns a system for conducting automated assays within a fluidic cartridge and its interfacing device on a sample containing specific biological or chemical substances that need to be detected. This disclosed system overcomes various limitation and constraints by assuring the simplicity of both the disposable cartridge and its interfacing system.